Encrypted messaging without internet, SIM, or a server to trust. Messages hop from phone to phone over Bluetooth mesh.
Every mainstream messenger depends on two things: a working internet connection and a central operator who can observe who is talking to whom. CoreTrust removes both dependencies. It treats network metadata — not just message content — as something worth protecting.
Multi-hop message routing over BLE. No internet or cellular required.
X25519 ECDH key exchange, AES-256-GCM payload encryption, HKDF-SHA256 key derivation.
Symmetric hash ratchet on every message, plus periodic full Diffie-Hellman re-keying.
Rotating routing tags and generated cover traffic to frustrate traffic analysis.
Android Keystore-backed keys, encrypted Room database, biometric lock, panic wipe, FLAG_SECURE.
Lightweight ACK packets confirm a message actually arrived.
Verify who you're talking to without phone numbers or usernames.
Group conversations discovered and joined over the mesh.
ML Kit-powered; text never leaves the device.
Each device holds an X25519 keypair generated on first launch. Two devices in range perform an ECDH exchange and derive a shared session key via HKDF-SHA256 — no central key server, no identity tied to a phone number.
Every message advances a symmetric hash ratchet, so recovering one message key doesn't expose earlier or later ones. A full DH re-key runs periodically on top of that.
Routing tags rotate instead of acting as persistent addresses, and a cover-traffic generator emits realistic dummy packets, making it harder for a passive observer to determine who is actually communicating.
Keys live in the Android Keystore (hardware-backed where supported); messages are stored in an encrypted Room database. A panic wipe destroys local data quickly and completely.
CoreTrust has not yet had an independent security audit. Until it does, treat it as a serious research/beta project rather than a hardened tool for high-risk situations.